ECSS Paris 2023: OP-AP13
INTRODUCTION: High-intensity interval training (HIIT) is frequently used to improve maximal physiological (e.g., VO₂max) or locomotor variables (e.g., maximal aerobic speed (MAS), maximal sprinting speed (MSS)) (Rosenblat et al., 2020). HIIT involves repeated bouts at intensities between the second lactate threshold and MAS, or sprints above MAS, i.e., sprint interval training (SIT). Previous literature does not favor one format over the other for physiological and locomotor adaptations (De Oliveira-Nunes et al., 2021). However, no study has analyzed the influence of an athlete’s locomotor profile on adaptations to HIIT and SIT. Therefore, we aimed to 1) evaluate differences in physiological and locomotor adaptations to HIIT vs. SIT and 2) analyze the influence of the locomotor profile on those adaptations. METHODS: Twenty-seven trained, male and female runners (27.67±7.45 years; n=12 women) completed pre- and post-testing comprising a 40-m sprint test to assess sprint performance (t40) and MSS and an incremental treadmill test to determine VO₂max, MAS, velocity at lactate threshold 1 and 2 (vLT1 and vLT2), peak treadmill speed (vpeak), and running economy (RE). Anaerobic speed reserve (ASR) was calculated by subtracting MAS from MSS and speed reserve ratio (SRR) as a ratio of MSS and MAS. The latter served to categorize participants as endurance, hybrid, or speed types. Further, they were stratified and assigned to six weeks training of two sessions HIIT (4-6x 4min/2min @90-95% MAS) or SIT (6-10x 20s/3min all-out sprinting) per week. Linear mixed models (Outcome=Time x Group + (1 | ID)) and linear models (%change=Group x Type) were calculated. RESULTS: Both groups showed significant improvements in MAS and vpeak (p≤0.03; d≥0.87), while MSS and t40 only improved in the SIT group (p≤0.04; d≥0.84). ASR declined and vLT2 inclined in the HIIT group only (p=0.01; d=0.41). VO₂max, vLT1, and RE did not change significantly (p≥0.08; d≤0.71). Independent of the group, MAS incline (p≤0.02; d≥2.25) and ASR decline (p≤0.02; d≥1.70) was higher for the speed compared to hybrid or endurance types. Endurance types improved t40 more in the SIT than HIIT group (p=0.003; d=-2.03) and more than hybrid types (p=0.03; d=2.03). VO₂max of speed types decreased in SIT but not in HIIT (p=0.04; d=-1.81). CONCLUSION: In conclusion, both HIIT and SIT improved endurance performance in trained runners, with SIT showing additional benefits for sprinting and HIIT for endurance (vLT2). Locomotor profiles influenced adaptations, with speed types showing greater MAS improvements and ASR declines, while endurance types benefited more from SIT in terms of t40. These results suggest that both training methods are effective and the specific benefits can vary based on the prescribed form of high-intensity exercise as well as the athletes locomotor profile. This highlights the potential of considering individual locomotor profiles when designing high-intensity training programs to optimize desired adaptations.
Read CV Maximiliane ThronECSS Paris 2023: OP-AP13
INTRODUCTION: The preparation period is a key time when players returning from a rest break are expected to improve their physical performance quickly and substantially in order to compete in a league lasting many weeks (Csala et al. 2021). The aim of this study was to investigate how the anaerobic threshold (ANT) and psychomotor fatigue threshold (PFT) change with the insertion of the 30-min block of high intensity interval training (HIIT) and normal training implemented during the preparatory period. METHODS: Twenty selected U-19 players playing daily in a professional football team were studied. The team was randomly divided by a group of players. The first group realized two times per week a 30-min block of HIIT exercises (HIIT), and the second group realized normal training (CON). The research was carried out in the Exercise Research Laboratory. The players performed an incremental progressive all-out test at the beginning of the round and after the preparatory period lasting 4 weeks. The measurement of lactate (LA) determined anaerobic threshold (ANT), whereas the choice reaction time (CRT) indicated psychomotor fatigue threshold (PFT) among other selected physiological parameters. The repeated-measure analysis of variance (ANOVA) compared mean values for the examined variables using the Fisher post hoc test. RESULTS: One of our main results is that the applied loads in the HIIT group significantly raised the anaerobic threshold at the velocity running from 13.20 to 14.49 km/h (p ≤ 0.000). In contrast, the CON group did not show any significant change, remaining at 13.26 km/h before and 13.20 km/h after the 4-week preparation period. Regarding the psychomotor fatigue threshold, the HIIT group initially reached 14.00 km/h, and after the preparation period, it significantly increased to 15.44 km/h (p ≤ 0.000). While the CON group also showed an increase, it was not statistically significant (from 13.75 to 14.12 km/h). CONCLUSION: One advantage of HIIT is its ability to improve physiological parameters and performance in a short amount of time (Buchheit and Laursen 2019). Finally, it was shown that the group performing an additional 30-minute block of interval training tested thresholds shifted towards higher loads - higher running speed. In addition, no significant changes were observed in the control group. This indicates that coaches should incorporate HIIT exercises in the preparatory period. References: 1. Csala et al. (2021) 2. Buchheit and Laursen (2019)
Read CV Paweł ChmuraECSS Paris 2023: OP-AP13
INTRODUCTION: Repeated-sprint training in hypoxia (RSH) provides greater training adaptations than a similar training performed in normoxia (RSN) in competitive athletes [1, 2]. RSH is recommend to be performed 2 to 3 sessions per week over several weeks at a simulated altitude of around 3000 m [1, 2]. However, implementation can be challenging due to limited access to a hypoxia environment, e.g., few infrastructures, congested schedules (e.g., work, school). Thus, it is important for athletes and coaches seeking to optimise training implementation to understand the minimal dose (e.g., frequency) of RSH required for desired training benefits. In particular, adhering to the recommended frequency (i.e., 2 to 3 sessions per week), can similar adaptations be attained by replacing some RSH sessions with RSN? This study aimed to determine effects of frequency of RSH on physiological and performance adaptations in male university basketball players. METHODS: Nineteen male university basketball players competing at a national level (20 ± 1 yrs, 181 ± 9 cm, 78 ± 12 kg, maximal oxygen uptake [V̇O2max]: 55.6 ± 5.7 ml·kg-1·min-1) completed 6 training sessions consisting of 2 to 3 sets of 5 to 6 repetitions of 6-s all-out cycle sprints (inter-sprint rest: 30 s; inter-set rest: 300 s) over 2 to 3 weeks. While 9 of them performed all 6 sessions in normobaric hypoxia at a simulated altitude of 3000 m (HYPO), the remaining 10 players performed RSH and RSN alternately (i.e., 3 sessions each, MIX). Before and after the intervention, average power (AP) during a 6-s all-out cycle test, and maximal incremental power (MIP) and V̇O2max achieved in an incremental cycle test were determined. RESULTS: A two-way (time and group) analysis of variance showed a significant main effect of time in all parameters (AP, MIP and V̇O2max, p <.05), whereas a significant time-by-group interaction effect was not observed in any of those parameters. Consequently, the magnitude of improvements was similar between the groups (HYPO vs. MIX: AP, 7.2 ± 7.7 vs. 9.8 ± 13.9%; MIP, 3.0 ± 3.5 vs. 3.5 ± 3.2%; V̇O2max, 2.9 ± 4.6 vs. 4.0 ± 7.7%). CONCLUSION: The frequency of RSH over a short period of time does not seem to impact physiological and performance adaptations in young male basketball players. Although RSH has been shown to be more effective than RSN in induing adaptations [1, 2], combined effects of RSH and RSN remained unknown. The findings of this study indicate that 50% of RSH sessions can be replaced by RSN without diminishing the degree of adaptations, thus offering flexible options for athletes and coaches, especially when facing congested schedules and limited access to a hypoxic environment. References 1. Brocherie, F., et al., Effects of Repeated-Sprint Training in Hypoxia on Sea-Level Performance: A Meta-Analysis. Sports Med, 2017. 47(8): p. 1651-1660. 2. Faiss, R., et al., Repeated-sprint training in hypoxia: A review with 10 years of perspective. J Sports Sci, 2024: p. 1-15.
Read CV Takaki YamagishiECSS Paris 2023: OP-AP13